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Cheers erupted from the Mars Perseverance EDL (Entry Descent Landing) war room as the rover completed its “7 Minutes of Terror” (a nickname for the 7 minutes of EDL where literally thousands of things have to go right) to safely land in the Jezero crater. The rover captured its entire Entry Descent and Landing on camera and is expected to transmit the video back to Earth later today.
NASA’s rover Perseverance is set to make its landing on Mars on February 18th. The rover launched for Mars on July 30, 2020 from Launch Complex 41 at Cape Canaveral Air Force Station, Florida aboard the hulking Atlas V-541 rocket. The largest of the interplanetary rockets, the V-541 stands 191 feet (58 meters) high with payload and weighing 1.17 million pounds (531,000 kg) fully loaded.
It took 6 months 19 days (203 days) traveling at a speed of 24,600 mph (about 39,600 kph) for Perseverance to make the 300 million mile journey to Mars. It’s set to touchdown in the Jezero crater which according to research was once a lake. The purpose of the mission is to find evidence of microbial life which could have existed during one of the crater’s wet times.
Landing this rover is technologically more challenging than previous rovers. Perseverance is too large to use the airbag method used in previous rover landings and the terrain where the rover is to land is also much more treacherous than previous landing areas. The landing is expected to take about 7 minutes not counting the pre-entry stage.
Ten minutes before entering the atmosphere, the spacecraft sheds its cruise stage, which houses solar panels, radios, and fuel tanks used during its flight to Mars. Only the protective aeroshell – with rover and descent stage inside – makes the trip to the surface.
Once the heatshield has slowed the spacecraft’s decent to under 1,000 miles per hour (1,600 kilometers per hour), a range-triggered parachute (a new technology) 70.5 feet (21.5 meters) in diameter will deploy at an altitude of around 7 miles (11 kilometers)
After the parachute deploys, the heat shield drops away and the rover is exposed to the atmosphere of Mars. At this time a new EDL technology – Terrain-Relative Navigation – kicks in. This technology uses a special camera to quickly identify features on the surface which are compared to an onboard map to determine the safest spot to land
Because of the low density of the Martian atmosphere, the parachute is only able to slow the vehicle to about 200 miles per hour (320 kilometers per hour). To safely touch down, the rover must free itself of the parachute at about 6,900 feet (2,100 meters) above the surface and ride the rest of the way down using the rocket powered descent stage. The descent stage diverts itself clear of the parachute and backshell coming down behind it.
The descent stage slows the descent speed to about 1.7 miles per hour (2.7 kilometers per hour) and begins the “Skycrane” maneuver. With about 12 seconds before touchdown, at about 66 feet (20 meters) above the surface, the descent stage lowers the rover on a set of cables about 21 feet (6.4 meters) long. Meanwhile, the rover unstows its mobility system, locking its legs and wheels into landing position.
As soon as the rover senses that its wheels have touched the ground, it quickly cuts the cables connecting it to the descent stage. This frees the descent stage to fly off to make its own uncontrolled landing on the surface, a safe distance away from Perseverance.
Attached to the bottom of Perseverance is one of the coolest parts of the mission, a small proof of concept helicopter called ingenuity. NASA’s Ingenuity Mars Helicopter is the first aircraft humanity has sent to another planet to attempt powered, controlled flight. Although it has no instruments and is just a ride-along Mars 2020 Perseverance mission, it has an important engineering mission of its own; to show that rotary flight is possible in the very thin atmosphere of Mars. The atmosphere of Mars is around 1% of earth’s, making these kinds of rotary powered flights extremely challenging.
Perseverance is carrying two microphones to Mars. One is an experimental mic to capture sounds of landing, and the other is for science. The atmosphere of Mars has a very different temperature, density, and chemistry than Earth, which has effects on sound.
The Perseverance rover will gather samples from Martian rocks using its drill. These sample cores will be stored in tubes on the Martian surface for a possible future mission to pick them up and bring them back to earth. This process is called “Sample Caching”. There are 43 sample tubes and 5 “Witness Tubes”. The Witness Tubes are pre-loaded with a variety of witness materials that can capture molecular and particulate contaminates from the rover or Earthly organic or inorganic material that may have arrived on Mars with the rover. These tubes will be used as experimental controls for the sample tubes.
Try this #CountdownToMars interactive feature to preview the difference: https://mars.nasa.gov/mars2020/participate/sounds/
1: MASTCAM-Z – Perseverance’s Mastcam-Z has improved 3D camera capabilities with the ability to zoom both lenses. Mastcam-Z will have the ability to view the landscape in a variety of colors (wavelengths of light), including some that can’t be detected by the human eye.
2: SUPERCAM – Fires a pulsed laser beam out of the rover’s mast, or “head,” to vaporize small portions of rock from a distance to identify the chemical composition of rocks and soils, including their atomic and molecular makeup. From more than 20 feet (~7 meters) away, SuperCam can fire a laser to study rock targets smaller than a pencil point. That lets Perseverance study spots it can’t reach with its arm.
3: MEDA – Mars Environmental Dynamics Analyzer will make measurements of the Martian environment including wind speed and direction as well as temperature and humidity. It will also measure the amount and size of dust particles in the Martian atmosphere
4: SHERLOC – Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals Mounted on the rover’s robotic arm, SHERLOC uses cameras, spectrometers, and a laser to search for organics and minerals that have been altered by watery environments and that may be signs of past microbial life. In addition to its black-and-white context camera, SHERLOC is assisted by WATSON, a color camera for taking close-up images of rock grains and surface textures.
5: PIXL – Planetary Instrument for X-ray Lithochemistry. PIXL uses an X-ray spectrometer which can identify chemical elements on a tiny scale. PIXL also has a camera capable of taking close up pictures of rocks and identifying particles as small as a grain of salt.
6: MOXIE – Mars Oxygen In-Situ Resource Utilization Experiment. The purpose of this instrument is to produce Oxygen from the Martian carbon-dioxide atmosphere. This will demonstrate a possible way for future explorers to produce oxygen for breathing and to use as a propellant.
7: RIMFAX – Radar Imager for Mars’ Subsurface Experiment will uses ground-penetrating radar to see geographical features underneath the surface of the ground beneath the rover.
Watch live #CountdownToMars coverage from NASA Jet Propulsion Laboratory, starting at 2:15 p.m. EST: https://go.nasa.gov/3k2VzmV
References:
https://mars.nasa.gov/